Feed collet



Nov. 28, 1933. G, AUGHUN 1,937,236

FEED COLLET Filed Jan. 16. 1933 Patented Nov. 28, 1933 UNITED sTATE-s pFEED: coLLE'r t Guy Laughlin, Birmingham, Mich. application January 16,19.33. ser-rar No; 652,071

Claims.

.' 5 Briefiy stated, one :of the aims of the invention is to provide afeed collet of, the type described in which thepads ,or work grippingelements are ,freely interchangeable to'allow of the employment of padsof Various sizes and configurations,

according to the size and cross-sectional formation of the work, ofwhatever nature it happens to be, all without removing the collet fromthe ,machine to which itis attached.V j

'Another aim ,of the invention is toprovide a feed collet of thedetachable pad type in which ,the resiliency of the fingers of thecollet is relied upon to hold the pads in place when the chuck is not inactual use.

-By way of further brief reference to the mounting of the pads it ispointed out that the longitudinal edge portions of the pads protrudebeyond thelongitudinal edges offlthe supporting fingers totdefinecontacting bearing lands or points that are freely grindable to allowthe resiliency of the body'to bring the pads Closer together and-therebycompensate for the wear that invariablytakes place as 'an incident tomovement `of stock through the chuck. A further aim is to provide a feedchuck of the type described, which is of highly simplifiedconstruction,cheap to manufacture, andionejwhich may be employed without departingfrom ,established production methods. w i i 1 z Other objects andadvantages will be apparent during the course of the followingdescription; i

In the accompanying drawing forming a part w of this application and inwhich like numerals are employed to designate like parts throughout thesame,

Figure l is a perspective of the improved feed collet, i

Figure 2 is an end view of the collet,

Figure 3 is a fragmentary side elevation of the collet in engagementwith a piece of work, a portion of the collet being broken away,

Figure 4 is a Vertical transverse sectional view of the oollet may beseparated to remove or attach thefiller. i

In the drawing, wherein for the purpose of illustration is shown apreferred embodiment of the invention, the numeral 5 generally.designates a tubular body, which may be formedlfrom pressed metal,tubing, cast metal or machined from solid stock, having the`conventional attaching means 6 in the form'of an externally threadedstem. If desired, the attaching means 6 maybe inthe form of aninternally'rthreaded stem. i It isclearly shown in Figuresl, 3 and'5that the tubular body is Vprovided-with a plurality of spaced parallel`lon'gitudinallyl extending,V slots 'opening out through the forward endof the body and defining'transversely curved spring leaves 8. Withparticular reference to Figure 3 it will be seen that the forward endportions of the leaves 8 are extended inward to define strengthening y`vand retaining Shoulders `10 of arcuate form, such i Shoulders beinglocated in Vadvance of circumferentialshoulders 12 formed, on the innersides of the vleaves. j ,i

'Ifhe Shoulders l;0 and 12 define what might be saidjto be lan annulargroove receiving'the outer portions of a filler embodying'a pluralityofarcur-l ate padsl4. vMore specifically, the pads 14 are snuglypositioned` between the shouldersglo and 12 and are held againstlongitudinal -shifting thereby. The pads 14 may be constructed fromdifferent-kinds of material, such as tool steel, :cast iron, bronze or;chromium plated to meet existing requirements. v I

It is shown in Figures 1,.5 and '7 that the pads 14 are increased incircumferential measurement toward points between the ends thereof andvthat the longitudinal edge portions of the pads protrude beyond thelongitudinaledges of the fingers 8 thereby defining opposed lands in theform of substantially equi-lateral triangles, said lands having apexesin engagement with each other to aid in securing the pads in place andbeing freely grindable to diminish the bore of the body. That is to say,when it is found that wear has enlarged the bore through the filler 14the edge portions of the pads and more particularly, the high points ofsaid edge portions may be ground an amount sufficient .to restore thebore of the filler to its original diameter. In this connection it isnoted that the ,pads and the shell are of dissimilar materials, the padsbeing of a more 'readily grindable material.`

Of course, the fingers 8 are tempered to press inwardly and in fact,such fingers are shown to converge toward the forward ends thereofurging the pads 14 in pressure engagement with the work.

It is shown in Figure 1 that when the improved Chuck is not actually inengagement with a piece of stock, theinherentresiliency of the fingersholds the pads securely in place and in this connection attention isinvited to Figures 3 and 4 in which it is illustrated` that a radialpin16 is carried by one of the leaves 8 and is received in an opening 18 inone of the pads so as to hold the pads against circumferential shifting,it being obvious that since the pads are in edge to edge engagement itis sufiicient in small sized collets to employ but a single pin toinhibit such circumferential shifting of the pads. However,. in largersized collets more than one of the radial pins 16 may be employed tohold the pads against circumferential shifting.

Should it be desired to remove the pads for the purpose of grinding thecontacting edges thereof, or for the substitution of pads of a differentsize or cross-sctional formation, it is a simple matter to spread theforward end of the shell with the aid of a suitable number of hand tools20, as shown in Figure 7,

More particularly, the forward portion of each 'hand tool 20 is providedwith an angularly directed bill of a size to fit easily between opposedVedges of the lfingers 8 so that when the tool is turned, the spacebetween the fingers will be increased allowing the pads to be easilydetached. Of course, as a prel'iminary to mounting the pads of therequired Character in the shell, the space lbetween the fingers istemporarily increased with 'the Vaid of the handtools 20. If desired,one hand tool may'be engaged with each pair of opposed edges of thefingers.

From the foregoing it will be seen that the feed chuck herein disclosedprovides a simple means by which the-master or shell may be employedincohjunction with nterchangeable pads providing a simple means Vby whichthe desired bore may be provided or maintained and it is shown inFigureVlthat the ends of the pads are beveledto 'allow 'o'f thefr'e'epassage of the work, the-bevel 'at the rear-'ends of the pads meetingthe adjacent corner` of the internal shoulder to prevent the jamming ofthe stock at this point.

-Having -thus described the invention, what is claimed i' S':'- I

- -'1. Ina feed collet, a tubular body having a bore 'and aV pluralityof spring fingers provided with spaced internal Shoulders, pads betweenthe shoul- 'itv ders and increased in circumferential measurement towardpoints between the ends thereof and having the longitudinal edgeportions thereof protruding beyond the longitudinal edges of the fingersthereby defining opposed lands in the form of substantially equi-lateraltriangles, said lands having apexes in engagement with each other to aidin securing the pads in place and being freely grindable to diminish thebore of said body.

2. In a feed collet, a tubular body having a bore and a plurality ofspring fingers, a filler within said body and having a series of arcuatepads increased in circumferential measurement toward points between theends thereof and having the longitudinal edge portions thereofprotruding be- ,yond the longitudinal edges of the fingers therebydefining opposed lands in the form of substantially equi-lateraltriangles, said lands having apexes in engagement with each other to aidin securing the pads in place, and being freely grindable to diminishthe bore of said body.

3. In a feed collet, a tubular body havinga bore and a plurality ofspring fingers, pads within the body and increased in circumferentialmeasurement toward points between the ends thereof and having thelongitudinal edge portions thereof protruding beyond the longitudinaledges of the fingers thereby defining opposed lands of triangular form,said lands having apexes in engagement with each other to aid insecuring the pads m place and being freely grindable to diminish thebore of said body.

4. In a feed collet, a tubular body having a bore 'and a plurality ofspring fingers, pads within the body and increased in circumferentialmeasurement toward points between the ends thereof and having theVlongitudinal edge portions thereof protruding beyond the longitudinaledges of the fingers thereby defining opposed lands of triangular form,said lands having apexes inengagement with each other to aid in securingthe pads in place and being freely grindable to diminish the bore 'ofsaid body, there being means holding the pads against circumferentialshifting.

i 5. Ina feed collet, a tubular body having a bore and a plurality ofspring fingers, pads within th`e bo'dy and increased in circumferentialmeasurement toward points between the ends thereof and having'thelongitudinal edge portions thereof protruding beyond the longitudinaledges of the fingers thereby defining protruding lands, said landshaving apexes in engagement with each other'to aid in securing the padsin place. w

` i GUY LAUGI-ILIN.

